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Topic: SoftwareSerial with ATTiny84 using ATtiny library (Read 51 times) previous topic - next topic

Coding Badly

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With some baud rates, the Arduino serial interface on my Mac receives some gibberish data and with others nothing at all. The TX led on the Arduino blinks when data is being sent btw.


Are you using your Arduino as a serial converter?

Coding Badly

Not sure how this is supposed to work without power...


It won't.

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...but just to test everything I tried it as well and the AtTiny stopped transmitting after pulling out the VCC cable.


Don't do that again.  It violates the specifications (meaning it could damage the processor).

daywalkerdha

No, I'm just trying to use the Arduino board as a serial interface because I don't have a separate one. The 84's TX pin goes to the RX pin on the Arduino Uno R3 board which makes the TX led blink on the Arduino board. I also connected a 10µF cap between RESET and GND on the Arduino and leave the 4 pins used for programming the 84 connected during testing. The only thing I change during programming is disconnecting the 84's serial line temporarily.


Coding Badly

No, I'm just trying to use the Arduino board as a serial interface because I don't have a separate one.


That is what I was trying to ask.  Got it.

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The 84's TX pin goes to the RX pin on the Arduino Uno R3 board which makes the TX led blink on the Arduino board.


I think that's correct.

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I also connected a 10µF cap between RESET and GND on the Arduino


The Arduino processor has to be removed (not recommended) or forced into reset (recommended).  Remove the 10µF capacitor.  Connect a jumper between RESET and GND.  (Actually, you can probably leave the capacitor in place.)

As you've discovered, the Arduino processor interferes with serial communications.  In addition, unless the Arduino processor is essentially removed from the circuit, it is possible to damage one or both processors (some current limiting resistors will protect both sides).


If you are interested, I have a version of the ArduinoISP sketch that makes what you are trying to do much simpler.

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